The invention relates to a system for handling effluent such as film processor effluent, and in particular to a system for discontinuously removing such effluent while minimizing unintended spillage of the effluent.
In chemical processing, and in particular the processing of photographic film such as that exemplified by the C41 process for silver halide films, the developing process releases silver from the films, leading to a liquid chemical effluent stream rich in silver which is classified as a hazardous material. This effluent stream must be collected and processed to remove the silver or collected and hauled away. Silver must be recovered from the effluent for both environmental and economic reasons.
There are 3 primary systems used today for dealing with effluent from a film processor:
(1) A hard-plumbed system to carry an effluent stream to a centralized effluent collection and/or processing point.
(2) A soft-plumbed system to carry the effluent stream to a nearby collection point. The collection container is then carried to a centralized effluent collection and/or processing location.
(3) A system of on-board holding tanks or containers mounted on the film processor. The tanks must be drained periodically. Typically this draining process consists of installing a temporary drain hose, actuating a manual drain valve and collecting the effluent in an open container. This container is then carried to a centralized effluent collection and/or processing location.
All three systems have shortcomings. While system 1 is operationally ideal, it requires expensive site facility modifications. It is well suited to high volume operations for which the cost of installation is most easily justified. However, it is less suitable for smaller operations. Systems 2 and 3 utilize an xe2x80x9copen containerxe2x80x9d silver recovery unit (SRU) where the effluent is simply poured into an SRU holding tank. These systems can become messy since the containers can be overfilled and spill. Even when no overfilling occurs, systems 2 and 3 can expose an operator to hazardous materials. Also, unintentional introduction of inappropriate liquids such as non-silver bearing effluent (developer) or cleaning supplies or other industrial liquids will damage the SRU. Finally, effluent which contains silver is a potential hazard if allowed to enter a sewer system.
Therefore, there is a need for an inexpensive system of handling silver-bearing effluent from a film processor such that the silver-bearing effluent is isolated thereby reducing risk of exposure to untreated effluent.
An effluent handling system of the invention includes a holding tank coupled through quick-disconnect fittings to an on-board effluent reservoir on a film processor. The holding tank receives effluent from the effluent reservoir, after which the holding tank and the effluent reservoir are uncoupled. The quick-disconnect fittings are self-sealing, that is, while permitting passage of fluid when coupled, they substantially preclude passage of fluid when uncoupled. The holding tank is transferred to a receiving station whereto it is similarly coupled, and effluent is discharged from the holding tank to the receiving station. The holding tank is then uncoupled from the receiving station and is available for recoupling to the effluent reservoir when required. The invention provides a simple connection between the holding tank and either the effluent reservoir or the receiving station, which substantially precludes unintended leakage or spillage of effluent from the system.